core: Make gpio optional

Former-commit-id: 2efe3a5486d76b2be0fc99abbe2e1ea14b21d180
Former-commit-id: b2ce408e12913a050354258b3e6f3c5e0714183d

rustboyadvance-core/src/cartridge/builder.rs

@@ -177,10 +177,10 @@ impl GamepakBuilder {
         let backup = create_backup(save_type, self.save_path);
 
         let gpio = match gpio_device {
-            GpioDeviceType::None => Gpio::new_none(),
+            GpioDeviceType::None => None,
             GpioDeviceType::Rtc => {
                 info!("Emulating RTC!");
-                Gpio::new_rtc()
+                Some(Gpio::new_rtc())
             }
             _ => unimplemented!("Gpio device {:?} not implemented", gpio_device),
         };

rustboyadvance-core/src/cartridge/mod.rs

@@ -40,7 +40,7 @@ pub struct Cartridge {
     pub header: CartridgeHeader,
     bytes: Box<[u8]>,
     size: usize,
-    gpio: Gpio,
+    gpio: Option<Gpio>,
     symbols: Option<SymbolTable>, // TODO move it somewhere else
     pub(in crate) backup: BackupMedia,
 }
@@ -49,7 +49,7 @@ impl Cartridge {
     pub fn get_symbols(&self) -> &Option<SymbolTable> {
         &self.symbols
     }
-    pub fn get_gpio(&self) -> &Gpio {
+    pub fn get_gpio(&self) -> &Option<Gpio> {
         &self.gpio
     }
 }
@@ -85,11 +85,13 @@ impl Bus for Cartridge {
     }
 
     fn read_16(&self, addr: u32) -> u16 {
-        if is_gpio_access(addr) {
-            if !(self.gpio.is_readable()) {
-                info!("trying to read GPIO when reads are not allowed");
+        if let Some(gpio) = &self.gpio {
+            if is_gpio_access(addr) {
+                if !(gpio.is_readable()) {
+                    warn!("trying to read GPIO when reads are not allowed");
+                }
+                return gpio.read(addr & 0x1ff_ffff);
             }
-            return self.gpio.read(addr & 0x1ff_ffff);
         }
 
         if addr & 0xff000000 == GAMEPAK_WS2_HI
@@ -114,9 +116,11 @@ impl Bus for Cartridge {
     }
 
     fn write_16(&mut self, addr: u32, value: u16) {
-        if is_gpio_access(addr) {
-            self.gpio.write(addr & 0x1ff_ffff, value);
-            return;
+        if let Some(gpio) = &mut self.gpio {
+            if is_gpio_access(addr) {
+                gpio.write(addr & 0x1ff_ffff, value);
+                return;
+            }
         }
 
         if addr & 0xff000000 == GAMEPAK_WS2_HI

rustboyadvance-core/src/debugger/command.rs

@@ -79,9 +79,7 @@ impl Debugger {
                 println!("IF={:#?}", self.gba.sysbus.io.intc.interrupt_flags);
             }
             GpuInfo => println!("GPU: {:#?}", self.gba.sysbus.io.gpu),
-            GpioInfo => {
-                println!("GPIO: {:#?}", self.gba.sysbus.cartridge.get_gpio());
-            }
+            GpioInfo => println!("GPIO: {:#?}", self.gba.sysbus.cartridge.get_gpio()),
             Step(count) => {
                 for _ in 0..count {
                     self.gba.cpu.step(&mut self.gba.sysbus);